This work will be a continuation of an effort to develop a completely automated procedure for tonal threshold audiometry in which the middle components of the averaged electroencephalic response (AER) are used as response indices. During this period emphasis will be on (1) the study of the effects of contralateral masking, (2) determination of the feasibility of threshold procedures on neonates, (3) determination of the mode of response analysis most adaptable to objective computerized response identification and quantification, (4) integration of a fully automated threshold procedure, and (5) validation of the automated procedure on patients with known auditory disorders. BIBLIOGRAPHIC REFERENCES: McFarland, W.H., Vivion, M.C., Wolf, K.E. and Goldstein, R. Reexamination of effects of stimulus rate and number on the middle components of the averaged electroencephalic response. Autiology, 14: 456-465 (1975). Vivion, M.C., Goldstein, R., Wolf, K.E. and McFarland, W.H. Middle components of human auditory AER: waveform variations during averaging. Audiology (In press).